Is there an app on android that can silence my phone according to gps position?

I wanna know if there is an app that can silence my phone while i am at a certain location by using GPS in my G1.|||I'm not sure. That would be a great app to make tho!|||Yes, its called Locale and cost $9.99. It also can change phone volume based on time of day and much more. For a video review- http://www.youtube.com/watch?v=sWEuuLoIa鈥?/a>